Chemistry 500
Dr. Hunter’s Class
Topic 2.
1
Chemistry 500: Chemistry in Modern Living
Topic 2: Protecting the Ozone Layer
Atoms and Light
Chemistry in Context, 2nd Edition: Chapter 2, Pages 35-72
Chemistry in Context, 3rd Edition: Chapter 2, Pages 45-92
Outline Notes by Dr. Allen D. Hunter, YSU Department of
Chemistry, 2000.
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
Chemistry 500
Dr. Hunter’s Class
Topic 2.
2
Outline
2A
WHAT IS OZONE? ...........................................................................................................................................3
2B
WHAT IS THE STRUCTURE OF A ATOM?................................................................................................6
2C
HOW DO WE KNOW MOLECULAR STRUCTURES? ............................................................................ 11
2D
HOW DO WE EXPLAIN MOLECULAR STRUCTURES? ....................................................................... 13
2E
WAVES OF LIGHT ........................................................................................................................................ 17
2F
WAVE/PARTICLE DUALITY ...................................................................................................................... 20
2G
THE OZONE SCREEN ................................................................................................................................... 21
2H
CFCS AND OZONE ........................................................................................................................................ 26
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
Dr. Hunter’s Class
Chemistry 500
2A What is Ozone?
 Ozone Formation
 Produced from a variety of processes:
 Photochemical Smog (Topic 1)
 High Voltage Electrical Discharges
Molecular Oxygen + Energy  Ozone
3 O2 + Energy  2 O3
 Can be smelled at 10 ppb
 Arc Welding
 Lightning Storms
 Laser Printers
 Tesla Coils
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
Topic 2.
3
Dr. Hunter’s Class
Chemistry 500
Topic 2.
4
 Allotropes
 Different forms of the same element
 They have different chemical structures
 Hence different chemical properties
 Examples include:
 Graphite (found in pencil lead) and Diamond (on rings)
are different chemical forms of the element Carbon
 Molecular Oxygen and Ozone are different chemical
forms of the element Oxygen
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
Dr. Hunter’s Class
Chemistry 500
Topic 2.
 The Allotropes of the Element Oxygen
 Molecular Oxygen, O2
 A Diatomic Molecule
 Liquefies at -183 C
 A light blue liquid
 Odorless
 Ozone, O3
 A Triatomic Molecule
 Liquefies at -112 C
 A dark blue liquid
 Used in water purification and pulp and paper bleaching
 Characteristic Odor

2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
5
Dr. Hunter’s Class
Chemistry 500
Topic 2.
6
2B What is the Structure of a Atom?
 Graphics from Text: Table 2.1, the Properties of Sub-Atomic
Particles
 Overview of Atoms and Nuclei
 Diagram Not to Scale!
 Nucleus actually tremendously smaller than the electron
cloud
 The Electron Cloud includes both Core Electrons and
Valence Electrons
e-
P+
N
N
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
Dr. Hunter’s Class
Chemistry 500
Topic 2.
7
 Electrons, e Surround the Nucleus
 Mass of 1/1838 AMU
 Charge of -1
 Protons, P+
 In the Nucleus
 Mass of 1 AMU
 Charge of +1
 Neutron, n
 In the Nucleus
 Mass of 1 AMU
 Charge of 0
 Neutron/Proton Ratio in Stable Nuclei
 Due to balance of Strong Nuclear Force and Electrostatic
Force
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
Dr. Hunter’s Class
Chemistry 500
Topic 2.
8
 Evidence for this structure
 High Energy Diffraction / Collision Experiments
 Rubber Baggie model of nucleus
 Isotopes
 The same element (i.e., the same number of protons in the
nucleus)
 Different Mass due to different number of Neutrons in the
Nucleus
 Chemically Isotopes react extremely similarly
 Examples:
 1H(Hydrogen), 2H (D, Deuterium), and 3H (T, Tritium)
 12C (common, 99%),
13
C (rare, 1%, NMR), and
rare, produced in upper atmosphere, radioactive)

238
U (non-radioactive) and 235U (radioactive)
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
14
C (very
Dr. Hunter’s Class
Chemistry 500
Topic 2.
9
 The Periodic Table
 Use the Periodic Table to Evaluate the Number of e-, P+,
and n in each isotope
 Atomic Number  The number of Electrons and Protons
in the neutral atom
 Mass Number

The total number of Protons and
Neutrons
He 
4
# e- =
# P+ =
#n =
Ar 
40
# e- =
# P+ =
#n =
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
Dr. Hunter’s Class
Chemistry 500
Topic 2. 10
 Ask Students: For each of the following isotopes, give the
total number of protons, neutrons, and electrons and then the
number of valence electrons and core electrons.
 Group Activity
Be 
7
# e- =
# P+ =
#n =
C 
13
# e- =
# P+ =
#n =
F 
19
# e- =
# P+ =
#n =
Si 
29
# e- =
# P+ =
#n =
183
W 
# e- =
# P+ =
#n =
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
Dr. Hunter’s Class
Chemistry 500
Topic 2. 11
2C How Do We Know Molecular Structures?
 How do we know molecular structures?
 Analytical Data
 Spectroscopic Methods
 Sporting Methods
 Specific absorption of light
 NMR = Nuclear Magnetic Resonance (cf. MRI, Magnetic
Resonance Imaging)
 Infra-Red (IR)
 Ultra Violet-Visible (UV-Vis)
 From the mid 1850s have know many molecular shapes but
were not able to explain them other than to say the atoms
were connected
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
Dr. Hunter’s Class
Chemistry 500
 X-Ray Crystallography/Diffraction
 Non-Sporting Method
 Single Crystals
 Hardware
 Data Collection
 Data Analysis
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
Topic 2. 12
Dr. Hunter’s Class
Chemistry 500
Topic 2. 13
2D How Do We Explain Molecular Structures?
 Theories change over time to better fit the experimental data
 A Theory should explain all current data and predict future
results
 Lewis Dot Structures
 Lewis developed this theory to explain know molecular
structures, reactivity data, and emerging ideas like electricity
and radioactivity
 Bonds were due to shared pairs of electrons
 Lone Pairs of Valence Electrons remain on many atoms
 Only the Valence Electrons Contribute to bonding
 This accounts for the fact that elements underneath one
another on the periodic table react similarly
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
Dr. Hunter’s Class
Chemistry 500
Topic 2. 14
 Rigorous Method of Determining Lewis Dot Structures
 Count the total number of valence electrons for the
molecules
 Distribute them around the atoms such that each atom gets
as close to a complete Octet as possible
 An Octet is 8 for most elements but 2 for Hydrogen and
Helium
 Some elements will allow / settle for greater or lesser
than 8 electrons but we won’t see these in Chem. 500
H
H
H
C
H
C
C
C
H
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
S
H
Dr. Hunter’s Class
Chemistry 500
Topic 2. 15
 Quick and Dirty Method for getting Lewis Structures
 An oversimplification that can break down but works well
for most Organic Compounds
 Bond Lengths
 Bond Angles
H  one bond and no lone pairs
F, Cl, Br, and I  one bond and three lone pairs
O, S, Se, and Te  two bonds and two lone pairs
N, P, As, and Sb  three bonds and one lone pair
C, Si, Sn, and Ge  four bonds and no lone pairs
H
H
H
C
H
C
C
C
H
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
S
H
Dr. Hunter’s Class
Chemistry 500
Topic 2. 16
 Ask Students: For each of the following molecules, draw the
correct Lewis Dot Structures including all Bonds and Lone Pairs
 Group Activity
H
H
O
H
H
C
C
C
C
H
H
H
H
H
H
Cl
C
C
C
Cl
H
H
C
H
O
O
C
H
H
H
H
H
C
C
I
H
Se
O
N
C
H
H
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
H
Dr. Hunter’s Class
Chemistry 500
Topic 2. 17
2E Waves of Light
 Graphics from Text: Figure 2.1, Wave Motion
 The relationship between Frequency, Wavelength, and
Amplitude for Electromagnetic Waves
 Electromagnetic Spectrum
 Wavelength of Electromagnetic Waves
 Long wavelengths correspond to low energy waves
 Is inversely related to the Frequency of Electromagnetic
Waves
 Wavelength = Speed of Light / Frequency
  = C / 
 C = Speed of Light = 3 x 108 m/sec
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
Dr. Hunter’s Class
Chemistry 500
Topic 2. 18
 Frequency of Electromagnetic Waves
 High frequency corresponds to high energy waves
 Is inversely related to the Wavelength of Electromagnetic
Waves
 Frequency = Speed of Light / Wavelength
  = C / 
 Amplitude of Electromagnetic Waves
 Is related to the intensity of the wave
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
Dr. Hunter’s Class
Chemistry 500
Topic 2. 19
 Graphics from Text: Figure 2.2, the Electromagnetic
Spectrum
 The relationship between frequency and wavelength for
various types of electromagnetic radiation
 Graphics from Text: Figure 2.3, Solar Radiation Profile
 The distribution of electromagnetic radiation of various
energies produced by the sun as they appear from just
above the earth’s atmosphere
 Note: the Overall Profile (Black Body Radiation)
 The Spikes and Valleys (Specific Absorptions by
Materials between the eye and the sun.
 Ask Students: As the temperature of the object changes, how
will the shape of Figure 2.3 change?
 Group Activity
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
Dr. Hunter’s Class
Chemistry 500
Topic 2. 20
2F Wave/Particle Duality
 Light is Wave Like
 Evidence includes Diffraction
 I.e., light bends
 Light is Particle Like
 Evidence includes Photoelectric Effect
 I.e., there is a threshold energy for light to cause its effects
 Wave / Particle Duality
 Light has Both Wave and Particle Like Properties
 Plank’s Relationship E = h 
 h is Plank’s Constant ( 6.63 x 10-34 joule seconds)
 Higher Frequency  Higher Energy
 Lower Frequency  Lower Energy
 Wave Packet Model
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
Dr. Hunter’s Class
Chemistry 500
Topic 2. 21
2G The Ozone Screen
 Graphics from Text: Figure 2.4 (3rd Edition only), Atmospheric
Sunscreen
 The atmosphere (and especially the Stratospheric Ozone
Layer) acts as sunscreen to select out which wavelengths of
light reach the earth’s surface
 Graphics from Text: Figure 2.4 in 2nd Edition and 2.5 in 3rd
Edition, Atmosphere’s effect on solar radiation reaching the
earth’s surface
 The atmosphere “screens” us from high energy UV light
reaching the surface
 Graphics from Text: Figure 2.5 in 2nd Edition and 2.6 in 3rd
Edition, Ozone’s Absorption of Ultra-Violet Radiation
 Ozone absorbs high energy UV light
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
Dr. Hunter’s Class
Chemistry 500
Topic 2. 22
 Molecular reasons for these effects
 Molecular Oxygen, O2, absorbs the highest energy UV light
 UV light with  less than about 242 nm
O2 + photon  2 O
 Ozone, O3, absorbs the medium energy UV light
 UV light with  less than about 320 nm (i.e., lower
energy)
 Ozone has a typical lifetime of about one or two hundred
seconds
 Ozone has a weaker O-O bond than molecular oxygen and
this bond is therefore broken by lower energy photons
O3 + photon  O2 + O
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
Dr. Hunter’s Class
Chemistry 500
Topic 2. 23
 Ozone Cycle
 Ozone generation in the atmosphere
O + O2  03 (formation of ozone)
 Graphics from Text: Figure 2.7 in 2nd Edition and 2.11 in 3rd
Edition, Ozone concentration profile of the atmosphere
 Ozone concentrations are highest in the part of the
stratosphere referred to as the Ozone Layer
 Graphics from Text: Figure 2.6 in 2nd Edition and 2.10 in 3rd
Edition, The Chapman Cycle of Ozone in the Atmosphere
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
Dr. Hunter’s Class
Chemistry 500
Topic 2. 24
 Ozone Destruction
 Free Radicals!!!
 Radicals are molecules or atoms with one or more
unpaired electrons
 This makes them extremely reactive and they can catalyze
reaction such as Ozone destruction
H2O + energy  H. + .OH
H. + O3  .OH + O2
OH + O  .H + O2
.
H. + O3 + .OH + O  .OH + O2 + .H + O2
Net Reaction:
O + O3  2 O2
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
Dr. Hunter’s Class
Chemistry 500
Topic 2. 25
 Ozone Loss
 Arctic and Antarctic Sensitivity
 Caused by extreme cold  tiny crystals whose surfaces
are involved in Ozone destruction
 Note: Noise levels in data
 Graphics from Text: Figure 2.8 in 2nd Edition and 2.7/2.12 in
3rd Edition, Average Ozone loss on the earth
 A few percent in continental US
 Graphics from Text: Figure 2.9 in 2nd Edition and 2.13 in 3rd
Edition, Ozone loss in Antarctica
 About 50% in the high Antarctic
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
Dr. Hunter’s Class
Chemistry 500
Topic 2. 26
2H CFCs and Ozone
 Halocarbons
 Compounds containing only C, Cl, F, Br, and H
 Are typically expensive but safe
 non-toxic, non-flammable, non-reactive, and quite volatile
 Used as refrigerants, blowing agents, propellants, cleaning
agents for computer parts, dry cleaning fluids, decaffination
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
Dr. Hunter’s Class
Chemistry 500
Topic 2. 27
 Classes of Halocarbons
 CFCs are Chlorofluorocarbons
 These are chemicals that contain only C, Cl, and F
 Examples include: CFCl3 (Freon 11) and CF2Cl2 (Freon
12)
 Halons contain C, Br, and F and/or Cl
 Examples include: CH3Br, CF2Br2 and CClBr3
 Used for fire extinguishers
 Chlorocarbons contain C, Cl, and H
 Examples include CCl3-CH3 and CH2Cl2
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
Dr. Hunter’s Class
Chemistry 500
Topic 2. 28
 Halocarbons and Ozone Destruction
 They are generally safe at ground level, why are they
dangerous in the Stratosphere?
 They are so stable that unlike most chemicals they escape
destruction in the decade or so it takes them to make it to
the Stratosphere
 This means that they can transfer Chlorine and Bromine
atoms here much better than other chemicals
 In the Stratosphere, these Cl and Br containing compounds
produce Cl. and Br. radicals which catalyze Ozone
destruction
 Bromine radicals are much less concentrated but are
much more destructive
 The man made examples of halocarbons are typically
more stable than the natural ones and therefore typically
make it to the Stratosphere better
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
Dr. Hunter’s Class
Chemistry 500
Topic 2. 29
 Reactions that destroy Ozone
CF2Cl2 + energy  CF2Cl. + .Cl
Cl. + O3  .OCl + O2
OCl + O  Cl. + O2
.
Cl. + O3 + . OCl + O  . OCl + O2 + .Cl + O2
O + O3  2 O2
Net Reaction:
 Note:
this reaction is very similar to that for Ozone
destruction by hydrogen radicals, it is just much faster and
thus more efficient
 The analogous reaction with bromine radicals is even
faster and more efficient
 Graphics from Text: Figure 2.11 in 2nd Edition and 2.15 in 3rd
Edition, Chlorine - Ozone Correlations
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
Dr. Hunter’s Class
Chemistry 500
 Solutions?
 Many now in place or being put into effect
 “Montreal Treaty”
 Cost Concerns
 Safety Concerns
 Technology Concerns
 Hydrochlorofluorocarbons
 Supercritical CO2
 Greenhouse gasses
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
Topic 2. 30
Chemistry 500
Dr. Hunter’s Class
Topic 2. 31
Index of Vocabulary and Major Topics
1
12
C ..............................................................................8
C ........................................................................ 8, 10
14
C ..............................................................................8
183
W ......................................................................... 10
19
F ............................................................................ 10
1
H ..............................................................................8
13
2
235
U ............................................................................8
U ............................................................................8
29
Si ........................................................................... 10
2
H ..............................................................................8
238
3
3
H ..............................................................................8
4
40
Ar ............................................................................9
4
He .............................................................................9
7
7
Be ........................................................................... 10
A
Allotropes .............................................................. 4, 5
Amplitude .......................................................... 17, 18
Analytical Data ........................................................ 11
Antarctic .................................................................. 25
Arc Welding ..............................................................3
Arctic ....................................................................... 25
Ask Students ................................................ 10, 16, 19
atmosphere .................................................................8
Atmospheric Sunscreen ........................................... 21
Atomic Number .........................................................9
Atoms ........................................................................6
Average Ozone loss on the earth ............................. 25
B
blowing agents ......................................................... 26
bond ......................................................................... 15
Bond Angles ............................................................ 15
Bond Lengths........................................................... 15
Bonds ....................................................................... 13
C
catalyze .................................................................... 24
CCl3-CH3 ................................................................. 27
CClBr3 ..................................................................... 27
CF2Br2...................................................................... 27
CF2Cl2 ...................................................................... 27
CFC ......................................................................... 27
CFCl3 ....................................................................... 27
CFCs and Ozone ...................................................... 26
CH2Cl2 ..................................................................... 27
CH3Br ...................................................................... 27
Chapman Cycle ....................................................... 23
Charge .......................................................................7
Chlorine - Ozone Correlations ................................. 29
Chlorocarbons.......................................................... 27
Chlorofluorocarbon ................................................. 27
cleaning agents for computer parts .......................... 26
Core Electrons ...........................................................6
Cost Concerns .......................................................... 30
D
D ..............................................................................8
decaffination ............................................................ 26
Deuterium ..................................................................8
Diamond ....................................................................4
Diatomic Molecule ....................................................5
Diffraction ............................................................... 20
dry cleaning fluids ................................................... 26
E
e- .......................................................................... 7, 9
E = h  ..................................................................... 20
Electrical Discharges .................................................3
electricity ................................................................. 13
Electromagnetic Spectrum ................................. 17, 19
Electromagnetic Waves ........................................... 17
Electron Cloud ...........................................................6
Electrons ................................................................ 7, 9
Electrostatic Force .....................................................7
element .................................................................. 4, 8
Energy .......................................................................3
expensive but safe .................................................. See
experimental data ..................................................... 13
F
Free Radicals ........................................................... 24
Freon ........................................................................ 27
Frequency .................................................... 17, 18, 20
C ............................................................................ 17
Carbon .......................................................................4
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
Chemistry 500
Dr. Hunter’s Class
G
Graphics from Text ................ 6, 17, 19, 21, 23, 25, 29
Graphite .....................................................................4
Greenhouse gasses ................................................... 30
Group Activity ............................................. 10, 16, 19
H
Halocarbons ....................................................... 26, 27
Halocarbons and Ozone Destruction ....................... 28
Halons ...................................................................... 27
How Do We Explain Molecular Structures ............. 13
How Do We Know Molecular Structures ................ 11
Hydrochlorofluorocarbons ....................................... 30
Hydrogen ...................................................................8
I
in Stable Nuclei .........................................................7
Infra-Red.................................................................. 11
intensity ................................................................... 18
IR ............................................................................ 11
isotope .......................................................................9
Isotopes ......................................................................8
L
Laser Printers .............................................................3
Lewis ....................................................................... 13
Lewis Dot Structures ............................................... 13
lifetime ..................................................................... 22
Light has Both Wave and Particle Like Properties .. 20
Light is Particle Like ............................................... 20
Light is Wave Like .................................................. 20
Lightning ...................................................................3
Liquefies ....................................................................5
lone pairs ................................................................. 15
Lone Pairs ................................................................ 13
M
Magnetic Resonance Imaging.................................. 11
Mass....................................................................... 7, 8
Mass Number .............................................................9
Molecular Oxygen ....................................... 3, 4, 5, 22
molecular shapes...................................................... 11
molecular structures ................................................. 11
Montreal Treaty ....................................................... 30
MRI ......................................................................... 11
N
n .......................................................................... 7, 9
Net Reaction ............................................................ 24
neutral atom ...............................................................9
Neutron ......................................................................7
Neutron/Proton Ratio .................................................7
Neutrons ....................................................................9
NMR .................................................................... 8, 11
Noise levels in data .................................................. 25
Topic 2. 32
non-flammable ......................................................... 26
non-reactive ............................................................. 26
non-toxic .................................................................. 26
Nuclear Magnetic Resonance .................................. 11
Nuclei ........................................................................6
Nucleus .................................................................. 6, 7
O
O2 .................................................................... 3, 5, 22
O3 .................................................................... 3, 5, 22
Octet ........................................................................ 14
Odorless .....................................................................5
Organic Compounds ................................................ 15
Oxygen ......................................................................4
Ozone..................................................... 3, 4, 5, 21, 22
Ozone concentration profile of the atmosphere ....... 23
Ozone Cycle ............................................................ 23
Ozone Destruction ................................................... 24
Ozone generation ..................................................... 23
Ozone Loss .............................................................. 25
Ozone loss in Antarctica .......................................... 25
P
P+ .......................................................................... 7, 9
pencil lead ..................................................................4
periodic table ........................................................... 13
Periodic Table ............................................................9
Photochemical Smog .................................................3
Photoelectric Effect ................................................. 20
photon ...................................................................... 22
Plank’s Constant ...................................................... 20
Plank’s Relationship ................................................ 20
propellants ............................................................... 26
properties ...................................................................4
Protons ................................................................... 7, 9
pulp and paper bleaching ...........................................5
Q
Quick and Dirty Method for getting Lewis Structures
............................................................................ 15
R
Radicals ................................................................... 24
radioactive .................................................................8
radioactivity ............................................................. 13
Reactions that destroy Ozone .................................. 29
refrigerants ............................................................... 26
Rigorous Method of Determining Lewis Dot
Structures ............................................................ 14
Rubber Baggie model of nucleus ...............................8
S
Safety Concerns ....................................................... 30
shared pairs of electrons .......................................... 13
Single Crystals ......................................................... 12
Spectroscopic Methods ............................................ 11
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University
Chemistry 500
Dr. Hunter’s Class
Speed of Light ......................................................... 17
Sporting Methods .................................................... 11
Stratosphere ............................................................. 28
Stratospheric Ozone Layer ...................................... 21
Strong Nuclear Force .................................................7
structures....................................................................4
Sub-Atomic Particles .................................................6
Supercritical CO2 ..................................................... 30
T
T ..............................................................................8
Technology Concerns .............................................. 30
Tesla Coils .................................................................3
The Ozone Screen .................................................... 21
Theory ..................................................................... 13
threshold energy ...................................................... 20
Triatomic Molecule ...................................................5
Tritium .......................................................................8
U
Ultra Violet-Visible ................................................. 11
Ultra-Violet Radiation ............................................. 21
unpaired electrons .................................................... 24
UV light ............................................................. 21, 22
UV-Vis .................................................................... 11
Topic 2. 33
V
Valence Electrons ................................................ 6, 13
volatile ..................................................................... 26
W
water purification .......................................................5
Wave / Particle Duality............................................ 20
Wave Motion ........................................................... 17
Wave Packet Model ................................................. 20
Wave/Particle Duality.............................................. 20
Wavelength .............................................................. 17
Waves of Light ........................................................ 17
What is Ozone ...........................................................3
What is the Structure of a Atom ................................6
X
X-Ray Crystallography/Diffraction ......................... 12

 ................................................................ 17, 18, 22

 ...................................................................... 17, 18
2000, Dr. Allen D. Hunter, Department of Chemistry, Youngstown State University